Selective indicating system



' L. HILLMAN SELECTIVE mbrcnine SYSTEI Filed Au 2a, 1943 INVHVTOR.

LEN MLMAN Patented Nov. 12, 1946' UNITED STATES PATENT OFFICE SELECTIVE INDICATING SYSTEM Leon Hlllman, New York, N. Y. Application August 28, 1943, Serial No. 500,397

(Granted under the act of March 3, 1883, as

7 Claims.

amended April 30, 1928; 370 0. G. 757) tem, an increase in the number of desired observations obviously, causes an increase in the number .of transmission lines required to carry the intelligence with the result that often, the cable resulting from the grouping of the individual lines becomes heavy and expensive with regard to the actual material required.

An object, therefore, of this invention is to provide a system for transmitting and indicating information of this type wherein a two-wire transmission line is employed regardless of the number of independent observations to be made.

To the accomplishment of the foregoing general object, and such other more specific objects as hereinafter appear, my invention consists in the apparatus elements and their relations to one another as are hereinafter described and sought to be claimed in the following specification. The specification is accompanied by a drawing in which the single figure is a schematic wiring diagram of my invention. I

Referring to the drawing wherein there is disclosed a transmitter A and a receiver B connected thereto by means of a two-wire cable, the transmitter comprises a commutator 2 which is of the split ring type including a plurality of fixed insulated segments 4-48. While the illustrated device shows eight such segments it will be understood that the invention is not limited to this number,

Electrical connection from each of the segments 4-I8 to the two-wire cable is made through graded resistors 20-34, one each 01 the resistors being connected at one terminal to one each of the segments 4-l8, while the other resistor terminals are connected in parallel and to one wire 36 of the two-wire cable. Rotatably mounted at the center of the commutator 2 is a contactor arm 38 which is connected to a rotatable standard bearing a meteorological element as for example a wind vane (not shown). Arm 38 is z electrically connected to the other line 31 of the two line cable by means of any convenient sliding contact. When the vane turns to assume a position determined by the direction of the wind, it causes a similar rotation of the contactor arm 38 which, by its connection to the line 31, completes the circuit through the particular segment with which it may be making wiping contact, and thence through the associated one of the resistors A conventional power supply is conveniently located at the receiver and, as shown in the figure, it comprises a rectifier 40 whose input is a 60 cycle volt supply, and-whose output is fed through a bleeder potentiometer calibrating control 42 to a parallel bank'of differentially operated electro-magnetic relays 4458. Meter M is provided in order to aid in the calibration of the relays to predetermined current sensitivities. In order to make these relays difierentially responsive to currents of varying magnitudes they may be formed of coils having graded numbers of turns, or, they may be provided with armatures Gil-14 of graded weights, or, the holdback springs (not shown) of each of the armatures may be maintained at varied tensions, or, any combination of the foregoing expedients may' be used for the same purpose. serially connected with said armatures is a bank of small electric light indicator bulbs Ht-90.- Thepower source for the bulbs may be the above-mentioned 60 cyclellO voltsupply across which is connected 2. step-down transformer 92. The secondary of the step-down transformer contains, in its output circuit, the relay contacts arranged in two rows with each row having eight contacts, the row 96 containing the break'wcontacts, with which armatures 60-14 are normally in engagement, and the row 94 containing the make contacts with which said armatures are pulled into engagement upon energization of coils 44-58.

Let it be assumed that the wind vane is directed so that the arm 38 makes contact with segment 4, as shown in the figure by the dotted line. When this is the case, resistor 20 is introduced into the circuit, and, assuming that said resistor is the lowest value resistor of the bank, the current in the two-wire cable is a maximum. Suitable adjustment of the calibrating control 42 may be made in order that, under such conditions all the relays 44--58 are energized sufficiently to throw all the armatures 60'l4 from their break position, as shown, into engagement with their make contacts in row 94. It will be obvious that, with all armatures in this position, current 3 will flow from terminal 96 of transformer 92, through lamp 90 and armature 14, to the terminal 94 of said transformer, only the lamp 50 passes enough current to cause it to glow, the other lamps I6-88 being effectively shorted out by the armature H.

When the direction of the wind shifts enough to cause the contactor arm 38 to wip across segment 6, resistor 22 replaces resistor 20 in the circuit and, provided that the former resistor is somewhat greater in value than the latter resistor, the current value in the circuit is reduced proportionately.

As a result, we find all the armatures 60-42 are drawn into make position, except armature 14 which, assuming that its relay coil 58 is insensitive to the current value now maintained, remains in break position. When this situation obtains, it will be clear that current will flow from terminal 96, armature I4, lamp 88 and armature 12, now in the make position,- to the terminal 94, so that only the lamp 88 passes current enough to make it light up, because contact 14 will short out lamp 90, the remainder being effectively shorted out by armature 12. In a similar manner, it may be shown that corresponding to each segment 4-l 8 with which the arm 38 may come into contact, there is one lamp which is made to glow. Thus, by merely observing the bank of bulbs to see which one happens to be lit, the observer may ascertain the direction of the wind at the transmitter.

It will be understood that other meteorological elements, as for example an anemometer, a rain fall measuring device, or wind velocity instrument, each provided with suitable gear mechanism to operatively connect the element to arm 38, may likewise be employed at the transmitter with similar results.

Having described the preferred form of my Invention, many modifications may become apparent to those skilled in the art and I wish it to be understood therefore-that my: invention is limited only by the scope of the appended claims.

I claim as my invention:

1. A selectively-operable electrical system comprising at least a pair of identical elements, a source of current normally disconnected from said elements, at least a pair of switches each having first and second positions, means including said switches when both are in their first positions to short circuit each of said elements,

means responsive to positioning of one of said switches to its second position while the other switch is in its first position to remove the short circuit from only one of said elements and to connect it across said source of current to cause operation of only said one element, and means responsive to positioning of both switches in the second position to remove the short circuit from only the other element and to connect it across said source to cause operation of only said other element.

2. A selectively-operable electrical signal system comprising at least a pair of identical signal elements, a source of current normally/"disconnected from said elements, at least a pair of relays each including contacts having first and second positions, means including said contacts when both are in their first positions to short circuit each of said elements, means responsive to positioning of one of said contacts to its second position while the other contact is in its first position to remove the short circuit from only one of said elements and to connect it across said source of current to cause operation of only said one element, and means responsive to positioning of both contacts in the second position to remove the short circuit from only the other element and to connect it across said source to cause operation of only said otherelement.

3. A selectively-operable electrical signal system comprising at least a pair of identical signal elements, a source of current normally disconnected from said elements, at least a pair of remotely controlled electromagnetic relay switches each having first and second positions. means including said switches when both are in their first positions to short circuit each of said elements, means responsive to positioning of one of said switches to its second position while the other switch is in its first position to remove the short circuit from only one of said elements and to connect it across said source of current to cause operation of only said one element, and means responsive to positioning of both switches in the second position to remove the short circuit from only the other element and to connect it across said source to cause operation of only said other element.

4. A system as set forth in claim 2, wherein said relays are graded so that they operate in response to different potentials applied thereto. said relays being connected in parallel to a source of variable potential.

5. A remote-control system comprising a pair of terminals adapted to be connected to a source of current, a network including a plurality of load circuits 'connected in end-to-end relationship, one end of said network being connected to one of said terminals, means to selectively complete the connection of said load circuits to the other of said terminals, said means'comprising a plurality of relays, each having an armature connected to a diiferent junction between said load circuits, each relay having a break-contact and a make-contact cooperating with its armature, said break-contacts being all connected to one of said terminals, and said make-contacts being connected to the other of said terminals.

6. A remote-control system comprising a pair of terminals adapted to be connected to a source of current, a network including a plurality of signal lamps connected in end-to-end relationship, one end of said network being connected to one of said terminals, means operable from a remote point to selectively complete the connection of said lamps to the other of said terminals, said 'I. A system as set forth in claim 6, wherein sai relays are graded so that they operate in response to different current strengths through their coils, means connecting all said coils in parallel with a source of current, and means at said remote point to vary said current.

LEON HILLMAN. 

